feat(cli): add claw config show command

Expose the merged runtime settings through a direct CLI subcommand so
users can inspect the effective configuration without entering the REPL.
The command prints the merged config as pretty JSON and is covered by
unit and end-to-end tests.

Constraint: Must preserve existing config precedence and read the same merged runtime config used by the CLI
Rejected: Reuse the text `/config` report output | user requested machine-readable JSON
Confidence: high
Scope-risk: narrow
Reversibility: clean
Directive: Keep `claw config show` aligned with `ConfigLoader` precedence rules if config discovery changes
Tested: `cd rust && cargo build --workspace`; `cd rust && cargo test --workspace`
Not-tested: Manual invocation against a real user config outside test fixtures

rust/crates/rusty-claude-cli/src/main.rs

@@ -122,6 +122,7 @@ fn run() -> Result<(), Box<dyn std::error::Error>> {
             model,
             permission_mode,
         } => print_status_snapshot(&model, permission_mode)?,
+        CliAction::ConfigShow => print_config_json()?,
         CliAction::Sandbox => print_sandbox_status_snapshot()?,
         CliAction::Prompt {
             prompt,
@@ -171,6 +172,7 @@ enum CliAction {
         model: String,
         permission_mode: PermissionMode,
     },
+    ConfigShow,
     Sandbox,
     Prompt {
         prompt: String,
@@ -356,6 +358,7 @@ fn parse_args(args: &[String]) -> Result<CliAction, String> {
         "agents" => Ok(CliAction::Agents {
             args: join_optional_args(&rest[1..]),
         }),
+        "config" => parse_config_args(&rest[1..]),
         "mcp" => Ok(CliAction::Mcp {
             args: join_optional_args(&rest[1..]),
         }),
@@ -396,7 +399,7 @@ fn parse_single_word_command_alias(
     model: &str,
     permission_mode_override: Option<PermissionMode>,
 ) -> Option<Result<CliAction, String>> {
-    if rest.len() != 1 || rest[0] == "branch" {
+    if rest.len() != 1 || matches!(rest[0].as_str(), "branch" | "config") {
         return None;
     }
 
@@ -418,6 +421,7 @@ fn bare_slash_command_guidance(command_name: &str) -> Option<String> {
         "dump-manifests"
             | "bootstrap-plan"
             | "agents"
+            | "config"
             | "mcp"
             | "skills"
             | "system-prompt"
@@ -701,6 +705,16 @@ fn parse_system_prompt_args(args: &[String]) -> Result<CliAction, String> {
     Ok(CliAction::PrintSystemPrompt { cwd, date })
 }
 
+fn parse_config_args(args: &[String]) -> Result<CliAction, String> {
+    match args {
+        [] => Err("Usage: claw config show".to_string()),
+        [action] if action == "show" => Ok(CliAction::ConfigShow),
+        [action, ..] => Err(format!(
+            "unknown config action: {action}. Usage: claw config show"
+        )),
+    }
+}
+
 fn parse_branch_args(args: &[String]) -> Result<CliAction, String> {
     match args {
         [] => Err("Usage: claw branch delete".to_string()),
@@ -3620,6 +3634,19 @@ fn print_sandbox_status_snapshot() -> Result<(), Box<dyn std::error::Error>> {
     Ok(())
 }
 
+fn print_config_json() -> Result<(), Box<dyn std::error::Error>> {
+    println!("{}", render_merged_runtime_config_json()?);
+    Ok(())
+}
+
+fn render_merged_runtime_config_json() -> Result<String, Box<dyn std::error::Error>> {
+    let cwd = env::current_dir()?;
+    let loader = ConfigLoader::default_for(&cwd);
+    let runtime_config = loader.load()?;
+    let parsed: serde_json::Value = serde_json::from_str(&runtime_config.as_json().render())?;
+    Ok(serde_json::to_string_pretty(&parsed)?)
+}
+
 fn render_config_report(section: Option<&str>) -> Result<String, Box<dyn std::error::Error>> {
     let cwd = env::current_dir()?;
     let loader = ConfigLoader::default_for(&cwd);
@@ -5914,6 +5941,8 @@ fn print_help_to(out: &mut impl Write) -> io::Result<()> {
         out,
         "      Show workspace status, origin/main freshness, active worktrees, and recent commits"
     )?;
+    writeln!(out, "  claw config show")?;
+    writeln!(out, "      Print the merged runtime config as JSON")?;
     writeln!(out, "  claw sandbox")?;
     writeln!(out, "      Show the current sandbox isolation snapshot")?;
     writeln!(out, "  claw dump-manifests")?;
@@ -5995,6 +6024,7 @@ fn print_help_to(out: &mut impl Write) -> io::Result<()> {
         out,
         "  claw --resume {LATEST_SESSION_REFERENCE} /status /diff /export notes.txt"
     )?;
+    writeln!(out, "  claw config show")?;
     writeln!(out, "  claw branch delete")?;
     writeln!(out, "  claw agents")?;
     writeln!(out, "  claw mcp show my-server")?;
@@ -6023,9 +6053,9 @@ mod tests {
         parse_args, parse_git_status_branch, parse_git_status_metadata_for,
         parse_git_workspace_summary, parse_git_worktrees, parse_recent_commits, permission_policy,
         print_help_to, push_output_block, render_config_report, render_diff_report,
-        render_diff_report_for, render_memory_report, render_repl_help, render_resume_usage,
+        render_diff_report_for, render_memory_report, render_merged_runtime_config_json,
-        resolve_model_alias, resolve_session_reference, response_to_events,
+        render_repl_help, render_resume_usage, resolve_model_alias, resolve_session_reference,
-        resume_supported_slash_commands, run_resume_command,
+        response_to_events, resume_supported_slash_commands, run_resume_command,
         slash_command_completion_candidates_with_sessions, status_context, validate_no_args,
         write_mcp_server_fixture, CliAction, CliOutputFormat, CliToolExecutor, GitBranchFreshness,
         GitCommitEntry, GitWorkspaceSummary, GitWorktreeEntry, InternalPromptProgressEvent,
@@ -6441,6 +6471,18 @@ mod tests {
         assert!(unknown_error.contains("Usage: claw branch delete"));
     }
 
+    #[test]
+    fn parses_config_show_subcommand() {
+        assert_eq!(
+            parse_args(&["config".to_string(), "show".to_string()])
+                .expect("config show should parse"),
+            CliAction::ConfigShow
+        );
+
+        let error = parse_args(&["config".to_string()]).expect_err("missing action should fail");
+        assert!(error.contains("Usage: claw config show"));
+    }
+
     #[test]
     fn parses_single_word_command_aliases_without_falling_back_to_prompt_mode() {
         let _guard = env_lock();
@@ -7111,6 +7153,16 @@ mod tests {
         assert!(plugins_report.contains("Merged section: plugins"));
     }
 
+    #[test]
+    fn merged_runtime_config_json_renders_pretty_valid_json() {
+        let rendered =
+            render_merged_runtime_config_json().expect("runtime config json should render");
+        let parsed: serde_json::Value =
+            serde_json::from_str(&rendered).expect("runtime config json should parse");
+        assert!(parsed.is_object());
+        assert!(rendered.starts_with("{\n") || rendered == "{}");
+    }
+
     #[test]
     fn memory_report_uses_sectioned_layout() {
         let report = render_memory_report().expect("memory report should render");
@@ -7441,6 +7493,7 @@ UU conflicted.rs",
         let mut help = Vec::new();
         print_help_to(&mut help).expect("help should render");
         let help = String::from_utf8(help).expect("help should be utf8");
+        assert!(help.contains("claw config show"));
         assert!(help.contains("claw branch delete"));
         assert!(help.contains("claw --resume [SESSION.jsonl|session-id|latest]"));
         assert!(help.contains("Use `latest` with --resume, /resume, or /session switch"));

rust/crates/rusty-claude-cli/tests/cli_flags_and_config_defaults.rs

@@ -5,6 +5,7 @@ use std::sync::atomic::{AtomicU64, Ordering};
 use std::time::{SystemTime, UNIX_EPOCH};
 
 use runtime::Session;
+use serde_json::json;
 
 static TEMP_COUNTER: AtomicU64 = AtomicU64::new(0);
 
@@ -160,6 +161,52 @@ fn config_command_loads_defaults_from_standard_config_locations() {
     fs::remove_dir_all(temp_dir).expect("cleanup temp dir");
 }
 
+#[test]
+fn config_show_command_prints_merged_runtime_config_as_json() {
+    // given
+    let temp_dir = unique_temp_dir("config-show");
+    let config_home = temp_dir.join("home").join(".claw");
+    fs::create_dir_all(temp_dir.join(".claw")).expect("project config dir should exist");
+    fs::create_dir_all(&config_home).expect("home config dir should exist");
+
+    fs::write(
+        config_home.join("settings.json"),
+        r#"{"model":"haiku","sandbox":{"enabled":true}}"#,
+    )
+    .expect("write user settings");
+    fs::write(
+        temp_dir.join(".claw.json"),
+        r#"{"permissions":{"allow":["git status"]},"sandbox":{"networkIsolation":true}}"#,
+    )
+    .expect("write project settings");
+    fs::write(
+        temp_dir.join(".claw").join("settings.local.json"),
+        r#"{"model":"opus","sandbox":{"filesystemMode":"workspace-only"}}"#,
+    )
+    .expect("write local settings");
+
+    // when
+    let output = command_in(&temp_dir)
+        .env("CLAW_CONFIG_HOME", &config_home)
+        .args(["config", "show"])
+        .output()
+        .expect("claw should launch");
+
+    // then
+    assert_success(&output);
+    let stdout = String::from_utf8(output.stdout).expect("stdout should be utf8");
+    let parsed: serde_json::Value =
+        serde_json::from_str(&stdout).expect("config show output should be valid json");
+    assert_eq!(parsed["model"], "opus");
+    assert_eq!(parsed["permissions"]["allow"], json!(["git status"]));
+    assert_eq!(parsed["sandbox"]["enabled"], true);
+    assert_eq!(parsed["sandbox"]["networkIsolation"], true);
+    assert_eq!(parsed["sandbox"]["filesystemMode"], "workspace-only");
+    assert!(stdout.starts_with("{\n"));
+
+    fs::remove_dir_all(temp_dir).expect("cleanup temp dir");
+}
+
 fn command_in(cwd: &Path) -> Command {
     let mut command = Command::new(env!("CARGO_BIN_EXE_claw"));
     command.current_dir(cwd);